The Underground is full of secrets, hidden items, and hilarious dialogue that you’ll miss if you rush. Ready to Start? Head over to the Quackprep Game List and search for Undertale Yellow
The most popular theory surrounding is that it refers to a legendary, cut boss fight named "The Quacken" or "Ducktor." According to fan mythos (largely spread via a now-deleted Steam guide from 2018), there is a hidden sequence in the game’s code that requires players to perform a specific, absurdly complicated ritual. quackprep undertale